My buddy Steve has a Go camera. It's been dropped, run over, submerged and hit whilest cycling, skiing and kayaking. He mounts either on top of his helmet or in a chest harness. It's a durable little sucker. Video quality seems good to me. Chest-mounted, it works well, on top of your brain bucket it's pretty tall compared to the bullet form factor IMHO. But no overhanging rocks or trees have broken it, a couple enough to knock him off the bike.
'91 Toyota Pickup
'09 Kawasaki KLR650
'12 Gunnar Rockhound 29
"They say the test of literary power is whether a man can write an inscription. I say, 'Can he name a kitten?'" -- Samuel Butler